Despite decades of attempts, curative immunological therapy against cancer has been very difficult to achieve, with the fundamental basis being antigen-recognition capacity, either by antibodies or through T cells (via the T cell receptor) (Cousin-Frankel, Science (2013) 342:1432). Antibody-based immunotherapies have been used extensively against cancer in instances where the target antigen is up-regulated in tumor cells as compared to normal cells (e.g., Her-2 in Her-2 amplified breast cancer), or in cases where the tumor cells express an antigen that can be recognized by the antibody or an antibody-toxin conjugate (e.g., Rituximab against CD20) (Baselga et al., Annals Oncology (2001) 12:S35). While clinical trials using antibody-based immunotherapies have shown improved patient survival in a limited number of cancer types (usually when combined with standard chemotherapy), these effects are often accompanied by significant safety and efficacy concerns (Cousin-Frankel Cancer, Science (2013) 342:1432).
Effective T cell therapies against cancers have been even more difficult to achieve clinically (Schmitt et al., Hum. Gene Ther. (2009) 20(11); 1240). An effective T cell therapy against cancer relies on a T cell with a high affinity binding directed against an antigen on a cancer cell. Chimeric antigen receptor T cells (CAR T cells) are widely used to recognize antigens on cells with both high affinity and specificity and without the requirement for accessory recognition molecules, such as HLA antigens to “present” peptides. The T cell receptor of a CAR T cells is “swapped” with an antigen-binding heavy and light chains, thereby obviating the need for HLA accessory molecules. The recombinant CAR T receptor is fused to signaling domains leading to activation of the T cell upon binding of the CAR T receptor to the target antigen.
The clinical use of CAR T cells has been limited to targeting a narrow range of cell surface antigens, further supporting the need for improved and novel approaches in the treatment of cancer. In particular, new approaches are needed for diseases such as acute myeloid leukemia (AML) in which the outcomes in older patients who are unable to receive intensive chemotherapy, the current standard of care, remains very poor, with a median survival of only 5 to 10 months (Dohner et al., NEJM (2015) 373:1136).
Described herein are novel approaches to cancer immunotherapy that targets certain classes of lineage-specific cell-surface antigens on tumor cells. The CAR T cell treatment is then combined with replacement of the non-tumor cells by infusion or reinfusion of a modified population of cells that are deficient for the lineage-specific cell-surface antigen. Recurrence of the tumor is prevented or decreased by maintaining surveillance of the patient in vivo with the CAR T cells.